Phylogenetic analysis of rhizobia nodulating with Acacia melanoxylon R. Br. and their nodulation effect on several woody legume plants

Abstract:

[Objective] Thirty four strains isolated from the root nodules of Acacia melanoxylon R. Br. in Fujian and Guangdong were studied about the taxonomic position in order to abundant germplasm resources of rhizobia. [Methods] 16S rRNA genes and housekeeping genes (atpD and glnII) of all 34 strains were sequenced, 14 type strains of which were used to perform phylogenetic analysis. Furthermore, some representative strains were chosen to perform nodule experiment. [Results] The results of phylogenetic analysis of 16S rRNA genes and housekeeping genes (atpD and glnII) were mostly in agreement with which of 16S rRNA PCR-RFLP. And 14 type strains were divided into 10 groups, 2 of which belonged to Mesorhizobium and the others were Bradyrhizobium. In addition, nodule experiment suggested that the tested strains have a large rang of hosts because they could nodulate with A. melanoxylon, Leucaena leucocephala, Albizia falcataria and Acacia aneura. Moreover, the growth promoting effect of these stains was significant when inoculated on A. melanoxylon and L. Leucocephala. [Conclusion] This study illustrated genetic and symbiotic diversity of rhizobia isolated from the root of A. melanoxylon.